Gidday,
This article appeared in our states sports aviation newsletter .The
beginning part you all already know but I have used it as a practice for my
touch typing. ( I wish I had a Dollar $ for every time I have used the
backspace key!)
:
This accident, which happened near the airport in Cornwall, Ontario,
involves the Rotax 912 engine used in many ultralights and advanced
ultralights, and so the information given below may help prevent a similar
occurrence.
During an overshoot at the airport in question, the engine lost oil pressure
and then failed, causing the aircraft to crash. The aircraft suffered
considerable damage but the occupants were not seriouly injured.
An examination of the engine revealed that a stainless steel clamp installed
on the No.2 exhaust pipe had worn a hole through the outboard end of the oil
pressure filter and allowed all of the oil to escape overboard. The spin-on
filter required by a manufacturer's directive was longer than the original
and reduced the clearance between the filter and the exhaust stack. It was
also observed that the exhaust pipe clamp to come into contact with the
filter and create a hole in it.
Further examination of this and other 912 engines in the operator's fleet
determined that several exhaust nuts were loose or torqued below the correct
value of 180 lbs. Some nuts were mussing and the studs, which require a
torque of 70 lbs, had backed out and detached with the nuts.
It was also noted that the operator re used exhaust stud lock nuts. Owners
of aircraft with 912 engines may wish to examine their engines for exhaust
system security and signs of interference with the oil filter.
Regards
Tony Renshaw
Builder No236
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